This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. The specific aim of this pilot proposal is to determine whether knockdown of Ldhc in the baboon testis can disrupt sperm function and serve as the basis for a male contraceptive technology. Goldberg and co-workers (Odet et al., Biol Reprod. 2008 Jul;79(1):26-34. Epub 2008 Mar 26) were successful in targeting disruption of the Ldhc gene in mice. Sperm from these males were unable to fertilize eggs. This observation validates LDHC as a target for contraceptive development. Our collaborator, Dr. Mark Saltzman, Yale University has been able to demonstrate that siRNA can be utilized in a biodegradable delivery system to knock down gene expression (personal communication) suggesting that targeting Ldhc in this way should be an effective male contraceptive. There is an obvious need for innovative contraceptive technology for men.